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authorMarcelo Tosatti <marcelo@kvack.org>2008-03-17 10:08:18 -0300
committerAvi Kivity <avi@qumranet.com>2008-03-25 10:22:17 +0200
commit15aaa819e20cb183f26392ed8ea16020630ef142 (patch)
tree28f7aa56ee06f60030384f2de99d10449d6e5ed8 /arch/x86
parent4b1a80fa65aa9e2ec5696998856136c886385538 (diff)
KVM: MMU: handle page removal with shadow mapping
Do not assume that a shadow mapping will always point to the same host frame number. Fixes crash with madvise(MADV_DONTNEED). [avi: move after first printk(), add another printk()] Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kvm/mmu.c13
1 files changed, 12 insertions, 1 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index e49c4d433c0..4ba85d95bd2 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -892,14 +892,25 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte,
int *ptwrite, gfn_t gfn, struct page *page)
{
u64 spte;
- int was_rmapped = is_rmap_pte(*shadow_pte);
+ int was_rmapped = 0;
int was_writeble = is_writeble_pte(*shadow_pte);
+ hfn_t host_pfn = (*shadow_pte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
pgprintk("%s: spte %llx access %x write_fault %d"
" user_fault %d gfn %lx\n",
__FUNCTION__, *shadow_pte, pt_access,
write_fault, user_fault, gfn);
+ if (is_rmap_pte(*shadow_pte)) {
+ if (host_pfn != page_to_pfn(page)) {
+ pgprintk("hfn old %lx new %lx\n",
+ host_pfn, page_to_pfn(page));
+ rmap_remove(vcpu->kvm, shadow_pte);
+ }
+ else
+ was_rmapped = 1;
+ }
+
/*
* We don't set the accessed bit, since we sometimes want to see
* whether the guest actually used the pte (in order to detect